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|
use axum::{
extract::State,
http::{HeaderName, StatusCode, header},
response::Json,
};
use sqlx::PgPool;
use strum::IntoEnumIterator;
use uuid::Uuid;
use crate::error::AppError;
use crate::extract::{AppJson, AppPath, AppQuery};
use crate::models::{
ListQuery, MeasurementData, MeasurementView, MetricType, MetricUnitPair, Order, Unit,
};
pub async fn health() -> StatusCode {
StatusCode::OK
}
pub async fn list_measurements(
State(pool): State<PgPool>,
AppQuery(query): AppQuery<ListQuery>,
) -> Result<Json<Vec<MeasurementView>>, AppError> {
Ok(Json(fetch_measurements(&pool, &query).await?))
}
pub async fn export_measurements(
State(pool): State<PgPool>,
AppQuery(query): AppQuery<ListQuery>,
) -> Result<([(HeaderName, &'static str); 2], Vec<u8>), AppError> {
let rows = fetch_measurements(&pool, &query).await?;
tracing::info!(count = rows.len(), "exporting measurements");
let mut writer = csv::WriterBuilder::new()
.has_headers(false)
.from_writer(Vec::new());
writer.write_record(["id", "measured_at", "metric_type", "value", "unit"])?;
for row in &rows {
writer.serialize(row)?;
}
let csv = writer
.into_inner()
.map_err(|e| csv::Error::from(e.into_error()))?;
Ok((
[
(header::CONTENT_TYPE, "text/csv; charset=utf-8"),
(
header::CONTENT_DISPOSITION,
"attachment; filename=\"measurements.csv\"",
),
],
csv,
))
}
async fn fetch_measurements(
pool: &PgPool,
query: &ListQuery,
) -> Result<Vec<MeasurementView>, AppError> {
let limit = match query.limit {
Some(x) if (x > 0) => Some(x),
None => None,
_ => return Err(AppError::BadRequest("limit must be positive")),
};
if let (Some(from), Some(to)) = (query.from, query.to)
&& from > to
{
return Err(AppError::BadRequest("from must not be after to"));
}
tracing::debug!(
from = ?query.from,
to = ?query.to,
metric_type = ?query.metric_type,
limit = ?limit,
order = ?query.order,
"fetching measurements"
);
// SQL can't bind ASC/DESC as a parameter. The CASE yields measured_at only when
// `order` is desc (sorted DESC) and NULL otherwise, so that key ties for every
// row and the ASC key decides the order. If this gets slow, use an if/else with a
// separate ASC and DESC query and add an index on measured_at.
let rows = sqlx::query_as!(
MeasurementView,
"
SELECT id, measured_at, metric_type, value, unit FROM measurement
WHERE ($1::timestamptz IS NULL OR measured_at >= $1)
AND ($2::timestamptz IS NULL OR measured_at < $2)
AND ($5::metric_type IS NULL OR metric_type = $5)
ORDER BY CASE WHEN $4 THEN measured_at END DESC,
measured_at ASC
LIMIT $3
",
query.from,
query.to,
limit,
matches!(query.order, Order::Desc),
query.metric_type
)
.fetch_all(pool)
.await?;
tracing::debug!(count = rows.len(), "fetched measurements");
Ok(rows)
}
pub async fn create_measurement(
State(pool): State<PgPool>,
AppJson(data): AppJson<MeasurementData>,
) -> Result<(StatusCode, [(HeaderName, String); 1], Json<MeasurementView>), AppError> {
let measurement = sqlx::query_as!(
MeasurementView,
"
INSERT INTO measurement (id, measured_at, metric_type, value, unit)
VALUES ($1, $2, $3, $4, $5)
RETURNING id, measured_at, metric_type, value, unit
",
Uuid::now_v7(),
data.measured_at,
data.metric_type,
data.value,
data.unit
)
.fetch_one(&pool)
.await?;
tracing::info!(
id = %measurement.id,
metric_type = ?measurement.metric_type,
"created measurement"
);
let location = format!("/measurements/{}", measurement.id);
Ok((
StatusCode::CREATED,
[(header::LOCATION, location)],
Json(measurement),
))
}
pub async fn get_measurement(
State(pool): State<PgPool>,
AppPath(id): AppPath<Uuid>,
) -> Result<Json<MeasurementView>, AppError> {
tracing::debug!(%id, "fetching measurement");
let measurement = sqlx::query_as!(
MeasurementView,
"
SELECT id, measured_at, metric_type, value, unit FROM measurement
WHERE id = $1
",
id
)
.fetch_one(&pool)
.await?;
Ok(Json(measurement))
}
pub async fn update_measurement(
State(pool): State<PgPool>,
AppPath(id): AppPath<Uuid>,
AppJson(data): AppJson<MeasurementData>,
) -> Result<StatusCode, AppError> {
let result = sqlx::query!(
"
UPDATE measurement
SET measured_at = $1,
metric_type = $2,
value = $3,
unit = $4
WHERE id = $5
",
data.measured_at,
data.metric_type,
data.value,
data.unit,
id
)
.execute(&pool)
.await?;
if result.rows_affected() == 0 {
return Err(AppError::NotFound);
}
tracing::info!(%id, "updated measurement");
Ok(StatusCode::NO_CONTENT)
}
pub async fn delete_measurement(
State(pool): State<PgPool>,
AppPath(id): AppPath<Uuid>,
) -> Result<StatusCode, AppError> {
let result = sqlx::query!("DELETE FROM measurement WHERE id = $1", id)
.execute(&pool)
.await?;
if result.rows_affected() == 0 {
tracing::debug!(%id, "measurement to delete did not exist");
} else {
tracing::info!(%id, "deleted measurement");
}
Ok(StatusCode::NO_CONTENT)
}
pub async fn metric_types() -> Json<Vec<MetricUnitPair>> {
Json(
MetricType::iter()
.flat_map(|metric_type| {
Unit::iter()
.filter(move |unit| metric_type.accepts(unit))
.map(move |unit| MetricUnitPair { metric_type, unit })
})
.collect(),
)
}
|
